The invention relates to mobile location devices, which make advantageous use of wireless transmission methods to provide device location information. Such location information may be the current geographical location of the device, and/or location dependent information. The mobile location devices may be dedicated location devices, but may alternatively provide other functionality, such as the ability to make telephone calls or provide user diary services, for example, as that provided by a Personal Digital Assistant (PDA).
The term mobile is used in the sense that it describes a device, which is not fixed in any one geographical location but moves location over time. Such devices may be portable and/or may be temporarily or permanently attached to any moveable object, such as a vehicle, person or animal. With such devices being moveable, and thus not always located near an external power supply, these devices often incorporate a built-in power supply, which would require periodic recharging and/or replacement. Nevertheless, in certain cases, a mobile location device may be temporarily or permanently driven by an external power supply, such as mains power or a vehicle battery in the case of a mobile location device permanently fixed to a vehicle and arranged to obtain power from the vehicle battery. All such forms of devices are within the scope of the present invention.